Subhypnotic propofol infusion plus dexamethasone is more effective than dexamethasone alone for the prevention of vomiting in children after tonsillectomy

Background: Postoperative vomiting (POV) is a common complication after tonsillectomy. Dexamethasone is known to decrease postsurgical vomiting. In this study, we compared the effects of dexamethasone alone to dexamethasone plus propofol on postoperative vomiting in children undergoing tonsillectomy. Methods: In a randomized double-blinded study, we evaluated 80 healthy children, aged 4-12 years, who underwent tonsillectomy with or without adenoidectomy. After anesthesia was induced by inhalation of sevoflurane, 0.15 mg.kg(-1) dexamethasone and 2 mu g.kg(-1) fentanyl was administered i.v. to all patients. The patients in the dexamethasone plus propofol group received 1 mg.kg(-1) propofol before intubation and continuously after intubation at a rate of 20 mu g.kg(-1).min(-1) until the surgery was completed. Data for postoperative vomiting were grouped into the following time periods: 0-4 and 4-24 h. Data were analyzed using a Student's t-test and chi-squared analysis. Results: The percentage of patients exhibiting a complete response (defined as no retching or vomiting for 24 h) increased from 37.5% in the dexamethasone-alone group to 75% in the dexamethasone plus propofol group (P = 0.001). Twenty-two patients (55%) in the dexamethasone-alone and nine patients (22.5%) in the dexamethasone plus propofol groups experienced vomited during 0-4 h (P = 0.003). Eight patients in the dexamethasone-alone group and three patients in the dexamethasone plus propofol group received ondansetron as a rescue antiemetic during the postoperative period. Conclusion: For children undergoing tonsillectomy, intraoperative subhypnotic propofol infusion combined with dexamethasone treatment provides a better prophylaxis against postoperative vomiting than does dexamethasone alone.